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1.
Oral Dis ; 30(2): 593-603, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36843542

RESUMO

OBJECTIVES: Intrapulpal calcifications can occur in the dental pulp of patients with diabetes. We focused on the association between ectopic calcifications in the dental pulp and advanced glycation end products (AGEs) in Spontaneously Diabetic Torii (SDT)-fatty rats, an obese type 2 diabetic rat model, to determine the mechanism of calcification with pulp stone in the dental pulp. MATERIALS AND METHODS: Pathologic calcification in the dental pulp of SDT-fatty rats was observed using electron microscopy and immunohistochemical analysis. Moreover, mechanical analysis of periapical region of molar tooth against occlusal force was performed. RESULTS: In SDT-fatty rats, pathogenic pulpal calcifications occurred during blood glucose elevation after 6 weeks, and granular calcification was observed in the dental pulp after 11 weeks. Pentosidine, a major AGE, and the receptor for AGEs were strongly expressed in the dental pulp of SDT-fatty rats. S100A8, TNF-α, and IL-6 also showed positive response in the dental pulp of the SDT-fatty rat, which indicated pulpal inflammation. Blood flow disorder and hypoxic dental pulp cells were also observed. In silico simulation, strain from occlusal force concentrates on the root apex. CONCLUSIONS: Glycation makes blood vessels fragile, and occlusal forces damage the vessels mechanically. These are factors for intrapulpal calcification of diabetes.


Assuntos
Calcificações da Polpa Dentária , Diabetes Mellitus Tipo 2 , Ratos , Humanos , Animais , Diabetes Mellitus Tipo 2/complicações , Reação de Maillard , Glicemia , Obesidade
2.
J Periodontal Res ; 58(4): 813-826, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37221815

RESUMO

BACKGROUND/AIMS: Hyperglycemia in diabetes is closely associated with periodontal disease progression. This study aimed to investigate the effect of hyperglycemia on the barrier function of gingival epithelial cells as a cause of hyperglycemia-exacerbated periodontitis in diabetes mellitus. METHODS: The abnormal expression of adhesion molecules in gingival epithelium in diabetes was compared between db/db and control mice. To study the effects of hyperglycemia on interepithelial cell permeability, the mRNA and protein expressions of adhesion molecules were investigated using a human gingival epithelial cell line (epi 4 cells) in the presence of either 5.5 mM glucose (NG) or 30 mM glucose (HG). Immunocytochemical and histological analyses were performed. We also studied HG-related intracellular signaling to assess abnormal adhesion molecule expression in the cultured epi 4 cells. RESULTS: The results of the proteomic analysis implied the abnormal regulation of cell-cell adhesion, and mRNA and protein expression assessments revealed the significant downregulation of Claudin1 expression in the gingival tissues of db/db mice (p < .05 vs control). Similarly, the mRNA and protein expressions of adhesion molecules were lower in epi 4 cells cultured under HG conditions than in those cultured under NG conditions (p < .05). Three-dimensional culture and transmission electron microscopy revealed reduced thickness of the epithelial cell layers with no flattened apical cells and heterogeneously arranged intercellular spaces among adjacent epi 4 cells under the HG. These results were consistent with the increased permeability of epi 4 cells under the HG relative to that of cells under the NG. This abnormal expression of intercellular adhesion molecules under the HG was related to the increased expression of receptors for advanced glycation end products (AGEs) and oxidative stress relative to that seen under the NG, along with stimulation of ERK1/2 phosphorylation in epi 4 cells. CONCLUSIONS: High glucose-induced impairment of intercellular adhesion molecule expression in gingival epithelial cells was related to the intercellular permeability of gingival cells, representing a possible link to hyperglycemia-related AGE signaling, oxidative stress, and ERK1/2 activation.


Assuntos
Diabetes Mellitus , Hiperglicemia , Humanos , Camundongos , Animais , Proteômica , Hiperglicemia/complicações , Hiperglicemia/metabolismo , Epitélio/metabolismo , Moléculas de Adesão Celular , Doença Crônica , Gengiva/metabolismo , Glucose/farmacologia , RNA Mensageiro/metabolismo , Molécula 1 de Adesão Intercelular/metabolismo
3.
Oral Dis ; 28(3): 745-755, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33539626

RESUMO

OBJECTIVE: The main aim of this study was to elucidate the effects of advanced glycation end products (AGEs) on the calcification of cultured rat dental pulp cells (RDPCs) and to investigate the crystallisation ability of glycated collagen. MATERIALS AND METHODS: AGEs were prepared via non-enzymatic glycation of a dish coated with type I collagen using dl-glyceraldehyde. To investigate the effects of AGEs on RDPCs, we performed WST-1 and lactate dehydrogenase assays; alkaline phosphatase, Alizarin Red S and immunohistochemical staining; and real-time quantitative reverse transcription PCR. In addition, we performed crystallisation experiments on glycated collagen. All microstructures were analysed using scanning electron microscopy/energy-dispersive X-ray spectroscopy and transmission electron microscopy/diffraction pattern analysis. RESULTS: AGEs did not affect the proliferation or differentiation of RDPCs, but enhanced the calcification rate and cytotoxicity. No major calcification-related genes or proteins were involved in these calcifications, and glycated collagen was found to exhibit a negative polarity and form calcium phosphate crystals. Cytotoxicity due to drastic changes in the concentration of pericellular ions led to dystrophic calcification, assumed to represent an aspect of diabetic pulp calcifications. CONCLUSION: Glycated collagen-containing AGEs provide a nurturing environment for crystallisation and have a significant effect on the early calcification of RDPCs.


Assuntos
Calcificações da Polpa Dentária , Diabetes Mellitus , Animais , Diferenciação Celular , Células Cultivadas , Polpa Dentária , Diabetes Mellitus/metabolismo , Produtos Finais de Glicação Avançada/genética , Produtos Finais de Glicação Avançada/metabolismo , Produtos Finais de Glicação Avançada/farmacologia , Ratos
4.
Clin Oral Investig ; 21(1): 309-317, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27003278

RESUMO

OBJECTIVES: The aim of the present study was to evaluate the bonding effectiveness of two resin core buildup systems using conventional methods in the field of adhesive dentistry and a new non-destructive method. MATERIALS AND METHODS: Twenty-four single-rooted human teeth were built up with dual-cure one-step self-etch adhesive and composite systems (SY1: Clearfil DC bond and Clearfil DC core automix, SY2: Clearfil bond SE one and Clearfil DC core automix one). The prepared samples were sectioned into approximately 1 × 1-mm-thick beams and subjected to micro-tensile bond strength (µTBS) testing (n = 24). The fractured beams after µTBS testing were analyzed by SEM and energy-dispersive X-ray (EDX) spectrometry. The three teeth filled with each resin core system were sectioned and embedded in epoxy resin to observe the dentin-bonding interface under TEM (n = 6). Moreover, three of each resin core-filled teeth without any processing were examined using µCT (n = 6). RESULTS: Two-way ANOVA revealed that the two factors "root region" (p < 0.001, F = 15.22) and "system" (SY1 < SY2; p < 0.001, F = 22.52) had a significant influence. The µTBS gradually decreased from the coronal side to the apical side of the root canal. Morphological evaluation revealed that SY2 was superior in terms of resin curing at the apical side. µCT non-destructive evaluation clearly revealed gap formation in SY1. CONCLUSION: SY2, which included a new light-independent catalyst, showed better bonding effectiveness and adhesive interface to dentin compared to that of SY1. CLINICAL RELEVANCE: The new catalyst, which is activated by contact with adhesive and resin composite, can be used for resin core buildup restorations.


Assuntos
Adesivos Dentinários/química , Técnica para Retentor Intrarradicular , Cimentos de Resina/química , Humanos , Técnicas In Vitro , Teste de Materiais , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Espectrometria por Raios X , Propriedades de Superfície , Resistência à Tração , Microtomografia por Raio-X
5.
PLoS Genet ; 9(12): e1003983, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24339795

RESUMO

Transcellular Mg(2+) transport across epithelia, involving both apical entry and basolateral extrusion, is essential for magnesium homeostasis, but molecules involved in basolateral extrusion have not yet been identified. Here, we show that CNNM4 is the basolaterally located Mg(2+) extrusion molecule. CNNM4 is strongly expressed in intestinal epithelia and localizes to their basolateral membrane. CNNM4-knockout mice showed hypomagnesemia due to the intestinal malabsorption of magnesium, suggesting its role in Mg(2+) extrusion to the inner parts of body. Imaging analyses revealed that CNNM4 can extrude Mg(2+) by exchanging intracellular Mg(2+) with extracellular Na(+). Furthermore, CNNM4 mutations cause Jalili syndrome, characterized by recessive amelogenesis imperfecta with cone-rod dystrophy. CNNM4-knockout mice showed defective amelogenesis, and CNNM4 again localizes to the basolateral membrane of ameloblasts, the enamel-forming epithelial cells. Missense point mutations associated with the disease abolish the Mg(2+) extrusion activity. These results demonstrate the crucial importance of Mg(2+) extrusion by CNNM4 in organismal and topical regulation of magnesium.


Assuntos
Amelogênese Imperfeita/genética , Proteínas de Transporte de Cátions/genética , Hipertricose/genética , Amaurose Congênita de Leber/genética , Magnésio/metabolismo , Retinose Pigmentar/genética , Amelogênese Imperfeita/patologia , Animais , Transporte Biológico/genética , Proteínas de Transporte de Cátions/metabolismo , Modelos Animais de Doenças , Epitélio/metabolismo , Humanos , Hipertricose/patologia , Amaurose Congênita de Leber/patologia , Camundongos , Camundongos Knockout , Mutação de Sentido Incorreto , Retinose Pigmentar/patologia
6.
J Endod ; 50(2): 243-251, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37918795

RESUMO

INTRODUCTION: A 65-year-old man had nonsurgical retreatment using an iodoform and calcium hydroxide paste in a maxillary left canine with persistent apical periodontitis. An apical mineralized barrier (AMB) was observed 3-months postoperatively. Unfortunately, the tooth was extracted due to a cementum tear. This provided an opportunity to analyze the AMB histologically, as there is a lack of previous reports on its microstructure. METHODS: After extraction and removal of the granulation tissue from the root surface, the canine was processed, and observed using micro-computed tomography (µCT) and light microscopy. Thereafter, the specimen was resin-embedded specimen was evaluated by scanning electron microscopy, micro-X-ray fluorescence spectroscopy and Raman spectroscopy to understand the mechanism and nature of the AMB formation during apical healing. RESULTS: Nonsurgical retreatment was clinically successful based on the absence of clinical symptoms of apical periodontitis and the radiographic presence of an AMB. The AMB was opaque and could be readily differentiated from dentin under a light microscope. Micro-computed tomography analysis revealed that the AMB had the same mineral density as dentin. Scanning electron microscopy revealed that the AMB had two distinct layers based on the size of the calcified particles. Elemental mapping using micro-X-ray fluorescence spectroscopy showed that the localization of calcium and phosphorus differed between AMB and other areas of biomineralization. Raman spectral mapping revealed that the surface layer of the AMB consisted of collagen, calcium carbonate, and hydroxyapatite. CONCLUSIONS: This study explored new analytical methods for elucidating the apical wound-healing process and the nature of the mineralized repair. The findings provided detailed information on the AMB highlighting a bilaminar structure with high calcium components higher on the inside and a brightness similar to cementum not dentin and the presence of hydroxyapatite.


Assuntos
Hidróxido de Cálcio , Hidrocarbonetos Iodados , Periodontite Periapical , Masculino , Humanos , Idoso , Hidróxido de Cálcio/uso terapêutico , Hidróxido de Cálcio/química , Cálcio , Microtomografia por Raio-X , Hidroxiapatitas
7.
J Prosthodont Res ; 68(2): 283-289, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-37286502

RESUMO

Purpose This study aims to evaluate the effects of resin primers containing methyl methacrylate (MMA) and silane agent on the bonding effectiveness of indirect resin composite blocks with three different filler contents.Methods A commercially available computer-aided design/computer-aided manufacturing (CAD/CAM) resin composite block and two experimental resin composite blocks with different filler contents were alumina-blasted and two surface treatments (primer and silane agent) were applied. The resin cement was built up, and the micro-tensile bond strength (µTBS) was measured after 24 hours, 1 month or 3 months of water storage (n = 24 per group). The fracture surfaces after µTBS measurements and resin block/cement interface were observed by scanning electron microscopy (SEM).Results The primer treatment group showed a significantly higher bond strength than the silane group only in F0 (filler content 0 wt%) group (P < 0.001). In the primer group, F0 and F41 (filler content 41 wt%) groups showed significantly higher bond strengths than F82 (filler content 82 wt%) group (P < 0.001). In contrast, in the silane group, F41 group showed significantly higher bond strength than F0 and F82 groups (P < 0.001), and F82 group showed significantly higher bond strength than F0 group (P < 0.001). SEM revealed that the matrix resin was partially destroyed on the fracture surface of the primer group, and an uneven interface surface was observed compared with that of the silane group.Conclusions MMA-containing primers showed higher bonding effectiveness to CAD/CAM resin composite blocks than the silane treatment.


Assuntos
Colagem Dentária , Silanos , Silanos/química , Propriedades de Superfície , Teste de Materiais , Cimentos de Resina/química , Resinas Compostas/química , Coroas , Resistência à Tração , Desenho Assistido por Computador
8.
J Electron Microsc (Tokyo) ; 61(5): 335-41, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22872279

RESUMO

Human enamel and dentin are hard and brittle mineralized tissues. It is difficult to prepare thin specimens (under 200 nm) of these tissues for transmission electron microscope observation without demineralizing them. We present a novel method of creating three-dimensional ultra-structural images of human enamel and dentin, using the focus ion beam (FIB) method and ultra-high-voltage electron microscope tomography. Thin specimens (less than 2 µm) of enamel and dentin were prepared using the FIB method. This method is appropriate for nano-fabrication of thin specimens for brittle materials such as enamel and dentin. It allows penetration of an ultra-high-voltage electron beam of a 3000 kV maximal acceleration voltage into a specimen, enabling projections of the specimen to be taken. It facilitates tomography of the enamel rods, sheaths, dentinal tubules and collagen fibrils with a high resolution of 2 nm. The component percentages in ultra-structures of dentin can be expressed numerically by using three-dimensional reconstruction images of tomograms. The matrix of peritubular dentin differed from that of intertubular dentin by having relatively fewer collagen fibrils. The major advantage of this method is its ability to visualize ultra-structural tomograms of highly calcified specimens without demineralization.


Assuntos
Esmalte Dentário/ultraestrutura , Dentina/ultraestrutura , Tomografia com Microscopia Eletrônica/métodos , Microscopia Eletrônica de Transmissão/métodos , Esmalte Dentário/química , Dentina/química , Colágenos Fibrilares/metabolismo , Humanos , Imageamento Tridimensional/métodos
9.
J Prosthodont Res ; 66(2): 288-295, 2022 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-34349083

RESUMO

PURPOSE: This study examined four cleaning methods and three chemical treatments for artificial saliva-contaminated fiber posts in terms of bonding durability to resin composite core materials. METHODS: Non-contaminated fiber posts (Tokuyama FR Post, Tokuyama Dental) and those contaminated (GC Fiber Post, GC) with artificial saliva (Saliveht Aerosol, Teijin Pharma) were used. Washing and drying (WD), alcohol cleaning (AlC), H3PO4 etching (P/WD), alumina blasting (B/D) for decontamination and silanization (Clearfil Ceramic Primer Plus, Kuraray Noritake Dental, Si), resin priming (HC Primer, Shofu, MMA), and bonding resin application (Clearfil Universal Bond Quick, Kuraray Noritake Dental, BR) for chemical treatment were performed. The treated fiber post was planted inside a cylindrical tube and filled with resin composite (DC Core Automix ONE, Kuraray Noritake Dental). The specimen was sectioned, and a push-out test was performed after 24 h, 1 month, and 3 months. The fracture surface was observed using a scanning electron microscope (SEM). RESULTS: Adhesion between the non-contaminated fiber post and resin composite did not improve by silanization and decreased by alumina blasting. SEM observations revealed a fractured glass fiber by alumina blasting. Saliva contamination decreased the bond strength between the fiber post and resin composite; however, recovery was achieved by WD, Alc, P/WD, and B/D. Compared to Si, BR (P = 0.009) was effective in restraining the long-term durability of bonding, whereas MMA (P = 0.99) was not. CONCLUSION: The application of bonding resin after alcohol cleaning is the most convenient and effective clinical procedure for fiber post surface treatment.


Assuntos
Colagem Dentária , Técnica para Retentor Intrarradicular , Óxido de Alumínio/química , Resinas Compostas/química , Colagem Dentária/métodos , Análise do Estresse Dentário , Teste de Materiais , Microscopia Eletrônica de Varredura , Cimentos de Resina/química , Saliva , Saliva Artificial , Propriedades de Superfície
10.
Pharmaceutics ; 14(10)2022 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-36297473

RESUMO

Gutta-percha points and root canal sealers have been used for decades in endodontics for root canal obturation. With techniques such as single cone methods, the amount of sealer is larger, making their properties more critical. However, relatively few reports have comprehensively evaluated their biological effects. To this end, we evaluated three types of sealers, zinc oxide-fatty acid-, bio-glass- and methacrylate resin-containing sealers were considered. Their biological effects were evaluated using a rat subcutaneous implantation model. Each sealer was loaded inside a Teflon tube and implanted subcutaneously in the backs of rats. Inflammatory cells were observed around all samples 7 days after implantation and reduced after 28 days. Our results revealed that all samples were in contact with the subcutaneous tissue surrounding the sealer. Additionally, Ca and P accumulation was observed in only the bio-glass-containing sealer. Furthermore, each of the three sealers exhibited unique immune and inflammatory modulatory effects. In particular, bio-glass and methacrylate resin sealers were found to induce variable gene expression in adjacent subcutaneous tissues related to angiogenesis, wound healing, muscle tissue, and surrounding subcutaneous tissue. These results may help to understand the biological impacts of root canal sealers on surrounding biological tissues, guiding future research and comparisons with new generations of materials.

11.
Dent Mater J ; 41(2): 317-322, 2022 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-34980768

RESUMO

A two-bottle self-curing universal adhesive (Tokuyama Universal Bond; Tokuyama Dental) that does not require a long waiting time or light curing after application of the bonding material has been developed. This study aimed to evaluate the influence of tooth and adhesive temperature during the bonding procedure on the effectiveness of dentin bonding. The results showed that the tooth temperature affected the effectiveness of the dentin bonding; therefore, to determine the precise bonding ability in the laboratory, the temperature of the tooth must be raised until it is the same as that of the oral cavity. In addition, the temperature of the material did not affect bonding effectiveness; this result confirms that it does not matter whether the refrigerated product is used soon after its removal from the refrigerator or after it reaches room temperature in the clinic.


Assuntos
Colagem Dentária , Adesivos Dentinários , Adesivos/química , Colagem Dentária/métodos , Cimentos Dentários , Dentina , Adesivos Dentinários/química , Teste de Materiais/métodos , Cimentos de Resina/química , Temperatura , Resistência à Tração
12.
Dent Mater J ; 40(4): 928-933, 2021 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-33775982

RESUMO

This study evaluated the bonding effectiveness of a newly developed two-step hydrophobic bonding material. Three groups using different bonding systems were compared: BZF group, using the new bonding system (BZF-29; GC, Tokyo, Japan); GPB group, using a one-step bonding system (G-Premio Bond; GC); and SE2 group, using a two-step bonding system (CLEARFIL SE Bond 2; Kuraray Noritake Dental, Tokyo, Japan). Microtensile bond strength (µTBS) was measured after storage in water for 24 h, 3 months and 6 months (n=25/group). Fracture surfaces were observed under scanning electron microscopy. The BZF group showed significantly higher µTBS than the other groups (p<0.001). Dominant failure patterns were cohesive failure for the BZF group (48-84%), mixed failure for the SE2 group (48-60%) and interface failure between adhesive and resin composite for the GPB group (48-52%). The hydrophobicity of the BZF-29 bonding system improves the long-term bonding effectiveness between adhesive and resin composite.


Assuntos
Colagem Dentária , Adesivos Dentinários , Resinas Compostas , Cimentos Dentários , Dentina , Teste de Materiais , Microscopia Eletrônica de Varredura , Cimentos de Resina , Resistência à Tração
13.
Front Cell Dev Biol ; 9: 596838, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34307338

RESUMO

The first and second branchiomeric (branchial arch) muscles are craniofacial muscles that derive from branchial arch mesoderm. In mammals, this set of muscles is indispensable for jaw movement and facial expression. Defects during embryonic development that result in congenital partial absence of these muscles can have significant impact on patients' quality of life. However, the detailed molecular and cellular mechanisms that regulate branchiomeric muscle development remains poorly understood. Herein we investigated the role of retinoic acid (RA) signaling in developing branchiomeric muscles using mice as a model. We administered all-trans RA (25 mg/kg body weight) to Institute of Cancer Research (ICR) pregnant mice by gastric intubation from E8.5 to E10.5. In their embryos at E13.5, we found that muscles derived from the first branchial arch (temporalis, masseter) and second branchial arch (frontalis, orbicularis oculi) were severely affected or undetectable, while other craniofacial muscles were hypoplastic. We detected elevated cell death in the branchial arch mesoderm cells in RA-treated embryos, suggesting that excessive RA signaling reduces the survival of precursor cells of branchiomeric muscles, resulting in the development of hypoplastic craniofacial muscles. In order to uncover the signaling pathway(s) underlying this etiology, we focused on Pitx2, Tbx1, and MyoD1, which are critical for cranial muscle development. Noticeably reduced expression of all these genes was detected in the first and second branchial arch of RA-treated embryos. Moreover, elevated RA signaling resulted in a reduction in Dlx5 and Dlx6 expression in cranial neural crest cells (CNCCs), which disturbed their interactions with branchiomeric mesoderm cells. Altogether, we discovered that embryonic craniofacial muscle defects caused by excessive RA signaling were associated with the downregulation of Pitx2, Tbx1, MyoD1, and Dlx5/6, and reduced survival of cranial myogenic precursor cells.

14.
Dent Mater J ; 40(6): 1445-1452, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34602585

RESUMO

The effects of silanization and resin primer application on CAD/CAM indirect resin composite block bonding were investigated. KATANA AVENCIA P blocks (Kuraray Noritake Dental) were treated with a silane coupling agent and/or a resin primer. The contact angles (CAs) of resin primer were observed before and after silanization. Panavia V5 (Kuraray Noritake Dental) was built after each treatment. Bond strengths were measured, and the interface was analyzed by energy dispersive X-ray spectroscopy (EDS). The CA showed that silane treatment improved the wettability of the resin primer to the resin block. The combination treatment of the silane and resin primer showed significantly higher bond strength than no treatment, only in the silanization or resin primer group (p<0.001 each). EDS analysis showed that the resin primer penetrated both cement and block sides. The combination of the silane and resin primer improved bonding effectiveness between the resin block and resin cement.


Assuntos
Colagem Dentária , Silanos , Resinas Compostas , Teste de Materiais , Cimentos de Resina
15.
J Prosthodont Res ; 65(4): 565-572, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34053974

RESUMO

Purpose This study evaluated the effects of different materials (composite resin system including a photo-cure adhesive (DC) vs. resin cement system including a self-etching primer (PV)) and techniques (direct vs. indirect) for resin core build-up on the bonding performance to root canal dentin.Methods The human teeth were decoronated and root canal preparation was performed. All specimens were randomly divided into four groups according to the combinations of the methods (Direct or Indirect) and the materials (DC: Clearfil DC Core, Kuraray Noritake Dental or PV: Panavia V5, Kuraray Noritake Dental). Micro-tensile bond strength (µTBS) and push-out tests were performed. Scanning electron microscope observations of the interface were also performed, and microcomputed tomography and optical coherence tomography were applied to evaluate the sealing ability.Results The Indirect group had significantly higher µTBSs than the Direct group in the DC group (P = 0.0076). The PV group had significantly higher bond strengths than the DC group in both the Direct and Indirect groups (P < 0.001). The Direct/PV group demonstrated significantly higher push-out bond strength than the Direct/DC group (P < 0.001). In the Direct/PV group, the formation of resin tags was observed even on the apical side of the canal. Microleakage was more clearly observed in the DC group than in the PV group.Conclusions PV has a higher bonding ability to root canal dentin than DC. When using DC, the indirect technique exhibited a higher bonding ability than the direct technique.


Assuntos
Colagem Dentária , Adesivos Dentinários , Humanos , Teste de Materiais , Resistência à Tração , Microtomografia por Raio-X
16.
J Prosthodont Res ; 64(3): 272-280, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31952931

RESUMO

PURPOSE: The purpose of this study was to evaluate the effect of pretreatment using phosphoric acid, sodium hypochlorite and sulfinic acid sodium salt on the bonding of one-step self-etching adhesives to root canal dentin. METHODS: Thirty-six single-rooted sound human premolars were randomly assigned into three groups before applying the one-step self-etching adhesive. These comprised a control group with no pretreatment, an NC group that received phosphoric acid and subsequent sodium hypochlorite gel pretreatments, and an NC+AC group that received an additional treatment with sulfinic acid sodium salt following the same pretreatment applied to the NC group. Microtensile bond strength measurements, bonding interface observations by scanning electron microscopy (SEM), elemental analyses by X-ray photoelectron spectroscopy (XPS) and degree of polymerization (DOP) analyses by Raman spectroscopy were subsequently performed. RESULTS: The bond strength was significantly higher in the NC+AC group than in the other two groups (Control: P=000.1 and NC: P=0.004). SEM observations showed that resin tags were present in the dentinal tubules in the NC and NC+AC groups. Compared to the control group, the adhesive resin layer had a lower DOP in the NC group, while the DOP for the NC+AC group was higher than that of the NC specimens. CONCLUSIONS: Bonding to root canal dentin was improved by applying sulfinic acid sodium salt in addition to treatment with phosphoric acid followed by sodium hypochlorite. The DOP of the adhesive resin was reduced by sodium hypochlorite and subsequently restored by applying sulfinic acid sodium salt.


Assuntos
Colagem Dentária , Hipoclorito de Sódio , Condicionamento Ácido do Dente , Resinas Compostas , Cavidade Pulpar , Dentina , Adesivos Dentinários , Humanos , Teste de Materiais , Microscopia Eletrônica de Varredura , Ácidos Fosfóricos , Cimentos de Resina , Sódio , Propriedades de Superfície , Resistência à Tração
17.
Dent Mater J ; 39(6): 1087-1095, 2020 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-32999261

RESUMO

The effect of cleaner containing 10-methacryloyloxydecyl dihydrogen phosphate (MDP) for removing temporary cement remnants on dentin surface was evaluated. Flat dentin surfaces were wet-polished (Co) and HY-BOND temporary cement hard (Shofu) was applied to the surface. This temporary cement was removed using an air-scaler (Sc), brush (Br), or phosphoric acid and NaOCl (NC). A prototype cleaner containing MDP (Kuraray Noritake Dental, Tokyo, Japan) was used with agitation mode (MC+AG). KATANA Avencia block (Kuraray Noritake Dental) was luted with SA Cement Plus Automix (Kuraray Noritake Dental). Co showed significantly higher bond strength than Sc or Br (p<0.001 each). Bond strengths with NC (p=0.99) and MC+AG (p=0.38) did not differ significantly from that with Co. Transmission electron microscopy revealed sufficient interaction of MC+AG. Cleaner containing MDP can effectively remove temporary cement by agitation, and can be expected to improve the chemical bonding ability by binding more MDP to dentin.


Assuntos
Colagem Dentária , Cimentos de Resina , Dentina , Adesivos Dentinários , Teste de Materiais , Metacrilatos , Cimento de Policarboxilato , Propriedades de Superfície , Resistência à Tração
18.
Front Physiol ; 11: 538835, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33123019

RESUMO

Epithelial fusion is critical in palatogenesis, and incomplete fusion results in various type of facial cleft, depending on the region that fails to fuse. In mammalian palatogenesis, the bilateral secondary palatal processes fuse in the middle of the face to form the secondary palate. Later, the dorsal side of the secondary palatal shelves fuses with the nasal septum to complete palatogenesis. Importantly, the anterior border of the secondary palatal shelf fuses with the primary palate, which is located at the anterior and ventral border of the nasal septum. While numerous studies have investigated the mechanism of fusion between secondary palatal shelves, very little is known about how the primary palate touches and fuses with the secondary palatal shelves. In this study, we investigate the possible epithelial cell behaviors on the surface of the primary palate using palatal explant cultures of K14-GFP mice. A time-lapse observation of the GFP-labeled epithelium and an SEM analysis revealed that the extrusion epithelium appeared at the region corresponding to the fusing area and expanded rostrally on the nasal septum surface in the absence of the secondary palatal processes. Unlike on the secondary palate surface, cellular migration and subsequent autonomous mesenchymal exposure were not evident on the nasal septum or the primary palate. TUNEL staining revealed that these extrusion epithelia were undergoing apoptosis. These findings indicated that extrusion with apoptosis was autonomously initiated at the presumptive region of the fusion without contact with the opposing secondary palate.

19.
J Prosthodont Res ; 64(3): 319-325, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32423658

RESUMO

PURPOSE: The purpose of this study was to evaluate the effectiveness of both a resin primer containing methyl methacrylate (MMA) and a silanizing agent on bonding to indirect resin composite blocks, using two types of build-up hybrid resin composites. METHODS: SHOFU BLOCK HC (Shofu) specimens were blasted with alumina, after which one of two surface treatments was applied: CERA RESIN BOND (Shofu, the Silane group) or HC primer (Shofu, the MMA group). Resin composites made using either Solidex Hardura (SDH, Shofu) or Ceramage Duo (CMD, Shofu) were built up and micro-tensile bond strength (µTBS) values were measured after storage in water for either 24h or 6 months (n=24 per group). The fracture surfaces after µTBS measurements and the resin block/build-up resin interfaces were observed by scanning electron microscopy (SEM). RESULTS: The bond strength of the Silane/SDH group significantly decreased after 6 months (p<0.001), whereas in the MMA group there was no significant loss after 24h or 6 months (p=0.99). In the CMD group, the bond strength after 6 months was significantly lowered in both the Silane group (p<0.001) and the MMA group (p<0.001), but the latter still showed greater adhesion. SEM images demonstrated that the matrix resin was partially destroyed at the fracture surfaces of the MMA group and fracture surface unevenness was observed. CONCLUSIONS: A primer containing MMA produced stronger bonding to CAD/CAM resin even after long-term aging compared to a silane treatment.


Assuntos
Colagem Dentária , Cimentos de Resina , Resinas Compostas , Desenho Assistido por Computador , Teste de Materiais , Microscopia Eletrônica de Varredura , Silanos , Propriedades de Superfície , Resistência à Tração
20.
Polymers (Basel) ; 12(4)2020 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-32316615

RESUMO

Vital pulp therapy is an important endodontic treatment. Strategies using growth factors and biological molecules are effective in developing pulp capping materials based on wound healing by the dentin-pulp complex. Our group developed biodegradable viscoelastic polymer materials for tissue-engineered medical devices. The polymer contents help overcome the poor fracture toughness of hydroxyapatite (HAp)-facilitated osteogenic differentiation of pulp cells. However, the composition of this novel polymer remained unclear. This study evaluated a novel polymer composite, P(CL-co-DLLA) and HAp, as a direct pulp capping carrier for biological molecules. The biocompatibility of the novel polymer composite was evaluated by determining the cytotoxicity and proliferation of human dental stem cells in vitro. The novel polymer composite with BMP-2, which reportedly induced tertiary dentin, was tested as a direct pulp capping material in a rat model. Cytotoxicity and proliferation assays revealed that the biocompatibility of the novel polymer composite was similar to that of the control. The novel polymer composite with BMP-2-induced tertiary dentin, similar to hydraulic calcium-silicate cement, in the direct pulp capping model. The BMP-2 composite upregulated wound healing-related gene expression compared to the novel polymer composite alone. Therefore, we suggest that novel polymer composites could be effective carriers for pulp capping.

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